<template>
    <div id="app">
      <div class="box">
        <div class="top"></div>
        <div class="middle"></div>
        <div class="bottom"></div>
      </div>
    </div>
</template>

<script>
import HelloWorld from './components/HelloWorld.vue'

export default {
  name: 'App',
  components: {
    HelloWorld
  }
}
</script>

<style lang='less' scoped>
#app {
  .box {
    width: 300px;
    height: 300px;
    border: 1px solid #dddddd;
    display: flex;
    flex-flow: column;
    .top {
      flex: 1;
      background-color: red;
    }
    .middle {
      flex: 1;
      background-color: yellow;
    }
    .bottom {
      flex: 1;
      background-color: green;
    }
  }
}
</style>
